1. Field of the Invention
The present invention is related to a door lock, and more particularly to a door lock which can be locked or unlocked by a key or a remote controller.
2. Description of Related Art
A conventional door lock, which can be lock or unlocked by a key or a remote controller, is composed of a bolt, a first sliding block and a second sliding block installed in a recess of the bolt, four links connected end to end to form a rhombic structure and installed in the first sliding block and the second sliding block by four connecting pins, and two torsion spring respectively mounted on the two transversally opposite connecting pins and pushing the two longitudinally opposite connecting pins. A first cam driven by a key is mounted at a first side of the bolt, and a second cam driven by a motor is mounted at a second side of the bolt. The motor is able to be actuated by a remote controller. The first cam and the second cam each have two tongues with an included angle of 180 degrees for pushing the bolt outwards to lock the door. An inner cover is mounted on the bolt, and the connecting pins extend out from slots on the inner cover. The connecting pin in the first block can be moved along a V-like slot in an outer cover when the first sliding block or the second sliding block being pressed by the first cam or the second cam. A stop is formed at a central portion of the V-like slot for preventing the bolt from being pushed inwards to unlock the door by an improper external force.
However, because there are a lot of space in the first and second sliding blocks, the links are loosely installed in the sliding blocks and often shake as the sliding blocks are pressed. Furthermore, when the bolt is locked and the second cam is anticlockwise rotated over to locate its tongue after a rear end of the bolt, the bolt is blocked by the tongue and can not be unlocked by a key anyway.
Therefore, the invention provides an improved door lock to mitigate and/or obviate the aforementioned problems.
The main objective of the present invention is to provide a door lock of which links are stably installed therein and will not shake when being pressed.
Another objective of the present invention is to provide a door lock of which a cam driven by a motor can not block a bolt when the bolt is unlocked by a key.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.